The upcoming release will be of a much more incremental nature as opposed to the rather big leap from 2.0 to 3.0.
We will have eventually plugins and works on SFTP are actually part of it. Having SFTP means first having good utilities to start connections in subprocesses. This is partly done for the purposes of IBM MQ connections but needs to be made more generic.
Its relation to plugins is that there is no knowing in advance what kind of plugins anyone will want to create so we need to support such cases as SFTP which require subprocesses to make sure every kind of connection will work, even if the underlying library is not 100% gevent-friendly.
Put differently, I realize that plugins are needed but I really want to make sure they can cover a wide range of use-cases (connection types) and for that some internal works are needed first.